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Teradata RDBMS Database Administration - NCR

NCR Teradata RDBMS Database Administration - NCR , 2004. - 616 p.
Download (direct link): teradatadatabaseadmin2004.pdf
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Dump Handling With No Fallback

To save space, you can modify Crashdumps temporarily to remove fallback.

Caution: Without fallback, you will not be able to access dump data if an AMP is down.

If an AMP goes down and Crashdumps has no fallback protection, the system handles a dump as follows:

The system will not copy any raw PDE dump data from the dump device areas into Crashdumps or Windows 2000 flat files until all AMPs are online.

If the copy operation is already in progress when an AMP goes down, the copy operation is deferred until after a restart brings the AMP online.

7 - 42

Teradata RDBMS Database Administration Chapter 8:

Archiving, Restoring and Recovering Data

This chapter discusses how to archive, restore and recover data on your Teradata RDBMS.

The topics about archiving data include:

Archive/Recovery (ARC) utility

Executing ARC commands using the BakBone NetVault plugin module for I Teradata |

The phases of archiving and restoring data

Considerations when restoring tables with partitioning |

ARC restore versus FastLoad

Creating archive script files

Session control

Archiving Data Dictionary tables in the DBC database

Recommended ARC routines

The topics about restoring data include:

Restore-related statements

Restoring after an AMP goes down

Information about recovering data includes:

Recovering data using ROLLFORWARD/ROLLBACKWARD operations

Using the CHECKPOINT Statement

Using the views of the Recovery Control Catalog (RCC)

For more information on the statements and procedures in this chapter, see

Teradata Archive/Recovery Utility Reference.

For a comparison of import/export utilities, including Archive/Recovery, see "Utilities Feature Comparison" in Appendix B: "Import/Export Utilities."

Teradata RDBMS Database Administration

7 - 1 Chapter 8: Archiving, Restoring and Recovering Data

Archive/Recovery (ARC) Utility

Archiving Overview

The Archive/Recovery (ARC) products include:

ARC running on an IBM channel-attached (mainframe) client or a Windows 2000 platform

ARC interfacing to NetVault (with a Teradata plugin) from BakBone Software, Inc.

The three major tasks of the Teradata RDBMS archive/recovery utility are:

Archive (capture user and/or dictionary data onto portable storage media)

Restore (restore data from portable storage media)

Recovery (roll forward or roll back changes to data from permanent journal tables)

Archive and recovery operates in two phases:

Data phase

Dictionary phase

An ARC operation can back up one or more databases or table, or all databases, for all-AMPs, a specific AMP, or an AMP cluster.

The optimum number of sessions for archive and recovery operations is:

For archive, one session per AMP

For restore or recovery, two sessions per AMP

8 - 2

Teradata RDBMS Database Administration Chapter 8: Archiving, Restoring and Recovering Data

Archive/Recovery (ARC) Utility

Archive/Recovery (ARC) Utility

The Archive/Recovery (ARC) utility archives, restores, recovers, and copies data. You use it to:

Archive a database or individual database table from Teradata to tape

Restore a database or individual database table to Teradata from tape

Restore a copied database or table to a different Teradata RDBMS |

Recover a database to an arbitrary checkpoint by rolling it backward or forward using before- or after-change images in a permanent journal table.

Delete a changed-image row from a permanent journal table. Common Uses for ARC

The Teradata system provides a number of automatic data protection features. However, these features do not cover all types of data loss. The ARC utility provides data protection for situations such as:

Loss of an AMP for non-fallback tables I

Loss of multiple AMPs in the same cluster |

Failed batch processes

Accidentally dropped tables, views, or macros

Miscellaneous user errors

Disaster recovery

ARC-Specific Terminology

The terms backup and dump are often used interchangeably with archive. Archive is the preferred term; the DUMP command is supported only for backward compatibility.

ARC is invoked by calling the program module ARCMAIN. Use RESTORE or COPY to reload archived data. There is no ARC command named "recover." |

COPY and RESTORE are specific ARC keywords and the names of ARC operations. In addition to reloading, they entail functions such as returning data tables to their state following modification (roll forward), returning data tables to the state they were in before they were modified (roll back), and so on.

The difference between a RESTORE operation and a COPY operation is:

RESTORE moves data from archived files to either the same Teradata system from which it was archived, or a different Teradata system if the DBC database (including the dictionary tables) has already been restored.
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